Curing is the process of controlling the rate and extent of moisture loss from concrete to ensure an uninterrupted hydration of Portland cement after concrete has been placed and finished in its final position. Curing of concrete must begin as soon as possible after placement & finishing and must continue for a reasonable period of time for the concrete to achieve its desired strength and durability as per relevant standards. Various methods, materials and procedures for curing of concrete are available but the principles involved are the same. In conventional construction, curing is done by ponding of water. If the ponded water leakes out or quickly evaporates, the structural components like bridge decks, flat roofs, pavements, etc., might not get proper curing. Following are the effects of improper curing of concrete: * Appearance of cracks on the concrete surface.
* Development of internal cracks due to heat of hydration. * Reduction in resistance to abrasion at the exposed surface. * Reduction in resistance to the action of frost and weathering. * Increase in the permeability of concrete and consequent decrease in the durability of concrete. Therefore, the need to develop Internal curing (or) Self curing method attracted several researchers.
Internal curing (or) Self curing is the process by which the hydration of cement occurs because of the availability of additional internal water that is not a part of mixing water. The following material can provide internal water reservoirs: * Super absorbent polymers
* Light weight aggregate
* Wood fibers
* Shrinkage reducing admixtures
The concept of self curing agents is to reduce the water evaporation from concrete, and hence increase the water retention capacity of the concrete compared to conventional concrete. To acquire knowledge on self curing concrete, it is proposed to investigate various properties...